Four gallons of gasoline cost 16.80. what is the price of gasoline in terms of gallons per dollar

One gallon cost $3.20

Step-by-step explanation:

You know that 4 gallons are %16.80.

So, you divide 16.80 by 4,

16.80:4

=3.2

Conclusion, 1 gallon is $3.20

Answer: 4.20

Step-by-step explanation:

One way to make this easier is to write the units.

You have $16.80 / 4 gallons. That's $4.20 per gallon, or we can write 4.20 dollars/gallon.

Since you want gallons per dollar, just invert the 4.20:

N gallons / dollar = (1/N) dollars / gallon:

1 / (4.20 dollars/gallon) = 0.2381 gallons / dollar.

I hope this makes sense.

(Sanity) Check: 0.2381 gallons for $1 ... That's a little less than one quarter gallon for $1, so if I wanted an entire gallon it would be a little over $4. Looks reasonable.